/*
import java.util.Scanner;
public class demo3 {
    private static volatile int flag = 0;
    public static void main(String[] args) {
        Thread t1 = new Thread(() -> {
            while (flag == 0) {
                // 循环体里, 啥都不写会触发内存可见性问题
            }
            System.out.println("t1 线程结束!");
        });
        Thread t2 = new Thread(() -> {
            System.out.println("请输入 flag 的值: ");
            Scanner scanner = new Scanner(System.in);
            flag = scanner.nextInt();
        });
        t1.start();
        t2.start();
    }
}*/

public class demo3 {
   private static volatile int count = 0;
    public static void main(String[] args) throws InterruptedException {
        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 50000; i++) {
                count++;
            }
        });
        Thread t2 = new Thread(() -> {
            for (int i = 0; i < 50000; i++) {
                count++;
            }
        });
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println(count);
    }
}